lost promo after account migration from Sprint

hello everyone i just want to say how totally digusted i am with Tmobile,i have a free line on us from Sprint(Sprint Customers: Free "Unlimited Line On Us Plan" - The Money Ninja)i resevered this line back in june 2020 when i was with sprint,now that my account got migrate to tmobile without my consent i am being,i have call umteen times to get this resolved but everytime i  get a new rep on the phone they told me they submit a request to management to get a code or someting new everytime to add to the account so i can get my promotions back,and told its gonna take 1 to 2 billing cycles,and they would credit the account for the promo line,after the 2 billing cycles the bill went back up and this repeats,now i am told i need to have 3 lines of service before i can get a third line free,that they cannot give me back the promo i had with sprint.I hope someone can reach out to fix this,i am truly disappointed with Tmobile